Analysis of microwave absorbers designed with FSS using the WCIP method
Microwave Absorbers, Frequency Selective Surfaces, Resistive FSS, WCIP
This work proposes a novel approach in analyzing microwave absorbers designed with frequency selective surfaces using the WCIP, Wave Concept Iterative Procedure. Microwave absorbers have become increasingly important in space-field applications, military applications, and wireless information security. They are designed to inhibit or attenuate electromagnetic reflections or transmissions. Frequency Selective Surfaces (FSS) are periodic two-dimensional structures composed of patch-like elements or apertures, which can be totally reflective or transmit without loss in the region near the resonant frequency of the elements. For information security applications, conventional frequency selective surfaces can be inserted into building walls to isolate or reduce interference. However, when used as a band reject filter, conventional FSSs can generate reflections, resulting in propagation delay and signal delay. The use of resistive FSSs as microwave absorbers has been analyzed to reduce the problems encountered in the use of conventional structures. To determine the behavior, resonance frequency and bandwidth of FSSs, design parameters such as type, shape, dimension and periodicity of the elements, dielectric characteristics and thickness are required. All parameters influence the wavelength, frequency of operation and the bandwidth of the FSS. Some classical techniques are used for FSS analysis, such as the Moment Method, Equivalent Circuit Method, and the Time Domain Finite Differences. These methods of analysis have unique characteristics that differ, presenting advantages for the analysis of certain structures in relation to others. However, they have limitations in relation to the type of structure analyzed, but they also require a great computational effort to perform accurate analyzes. The Iterative Method of the Waves is constantly improving and has characteristics that make it a powerful tool for the characterization of planar structures. It is due to the low computational effort involved and the flexibility of the shapes of the structures, bringing advantages such as ease of implementation, fast execution and low computational effort. Thus the main objective of this work is to develop a new technique of computational analysis based on WCIP applied to multilayer microwave absorbers, designed with conventional and resistive FSSs.